title: Prevalence and molecular epidemiological typing of penicillinase-producing Neisseria gonorrhoeae and their bla(TEM-135) gene variants in Nanjing, China.
abstract: BACKGROUND
  This study aimed to investigate the prevalence of penicillinase-producing Neisseria gonorrhoeae (PPNG) and their blaTEM-135 gene variant in 2007 and 2012 in Nanjing, China. In addition, molecular epidemiological typing of all isolates was performed to elucidate the genetic relationships of the PPNG strains.
  
  
  METHODS
  A total of 199 and 77 N. gonorrhoeae isolates were collected at the National Center for STD Control in 2007 and 2012, respectively. Nitrocefin tests were performed to identify PPNG. Mismatch amplification mutation assay was used to identify blaTEM-135. All isolates were genotyped using N. gonorrhoeae multiantigen sequence typing (NG-MAST), and additionally, porB-based phylogenetic analysis was performed for the PPNG isolates.
  
  
  RESULTS
  The total prevalence of PPNG isolates was 41% (114/276) and 58% (66/114) of these PPNG isolates possessed bla(TEM-135). In 2007, 45% (90/199) produced β-lactamase, and of those PPNG, 58% (52/90) possessed bla(TEM-135). In 2012, 31% (24/77) were PPNG, and 58% (14/24) of those isolates contained bla(TEM-135). There were 162 NG-MAST STs among the 276 isolates, and 89 of those were novel STs. A strong association between specific NG-MAST STs and bla(TEM-135) was found, and the porB-based phylogenetic analysis showed a distant evolutionary relationship between isolates in 2007 and isolates in 2012.
  
  
  CONCLUSIONS
  A high prevalence of PPNG and blaTEM-135 was found in Nanjing, China. bla(TEM-135) might be a precursor in the evolution into an extended-spectrum β-lactamase that can degrade ceftriaxone, which stresses the need to continuously monitor PPNG, blaTEM-135, and additional evolving blaTEM gene variants.
authors.affiliation: From the *National Center for STD Control, China CDC, and Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College,and Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, China; †National Institute of Infectious Diseases, Tokyo, Japan; and ‡WHO Collaborating Centre for Gonorrhoea and Other STIs, Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden.
authors.forename: Shao-Chun
authors.initials: SC
authors.lastname: Chen
authors.forename: Yue-Ping
authors.initials: YP
authors.lastname: Yin
authors.forename: Xiu-Qin
authors.initials: XQ
authors.lastname: Dai
authors.forename: Rui-Xing
authors.initials: RX
authors.lastname: Yu
authors.forename: Yan
authors.initials: Y
authors.lastname: Han
authors.forename: Hou-Hua
authors.initials: HH
authors.lastname: Sun
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohnishi
authors.forename: Magnus
authors.initials: M
authors.lastname: Unemo
authors.forename: Xiang-Sheng
authors.initials: XS
authors.lastname: Chen
mesh_terms: D002681:China / Q000453:epidemiology; D004352:Drug Resistance, Microbial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D006069:Gonorrhea / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification*; D010405:Penicillinase / Q000494:pharmacology*; D010802:Phylogeny; D011159:Population Surveillance; D012703:Serotyping
chemical_list: D010405:Penicillinase